| For improving the structure of the steel surface or the surface processing, the strong acid were used to cleaning the steel surface. Thus, a large number of pickling waste liquor produced which contain high concentration of iron and other metal ions and form acid mist easily. It will cause serious environmental pollution if they were discharge directly. And while using traditional neutralization processing method, a lot of environmental problems such as sludge will appear, meanwhile cause the waste of useful resources, such as iron and waste acid. In the study, the pretreatment pickling waste liquor from a steel factory in Guangdong province were used to prepare high value-added products on the basis of understanding properties. And in order to find a possible combination treatment for the recycling of pickling waste liquor and to provide guidance engineering application. The main results are as follows.(1)Polymeric aluminum ferric chloride flocculants (PAFC) of different aluminum iron ratio were prepared with the method of oxidation polymerization, combined with aluminum scrap from aluminum processing plant. The best preparation conditions were found in the orthogonal experiment, whose polymerization temperature was75℃and polymerization length was1h. The optimum pH before oxidation of PAFC, whose aluminum iron ratio was9:1, was1.91through the single factor conditions. Similarly, the optimum pH before oxidation of PAFC with aluminum iron ratio of8:2,7:3and6:4were1.98,2.35and2.97respectively. Self-made PAFC of different aluminum iron ratio had obvious effect on removal of low concentration acid red73. The removal rate was up to80%and the effluent chroma satisfied the special emission limits of discharge standard. The removal efficiency on low concentration acid red73was better than commercially available polyaluminium chloride’s (PAC), and fair with the commercially available PAFC’s. It was found that self-made PAFC had a high-added value by means of cost budget.(2)The oleic acid modified magnetic Fe3O4(OA-Fe3O4) nanoparticles were prepared by using ultrasonic assisted chemical co-precipitation, and then magnetic liquid appeared by Fe3O4nanoparticles dispersed in cyclohexane. The OA-Fe3O4was characterized by X-ray diffraction (XRD), Fourier infrared spectrometer (FTIR) and synchronous thermal analyzer (TGA). The results show that a proper amount of oleic acid adsorbed on the Fe3O4nanoparticles surface rely on chemical bonds. While, double-layer adsorption appeared when the oleic acid content value was too high, lining was through the chemical bond between the carboxylate groups of oleic acid and Fe3O4nanoparticles, and the exterior was through the oil-wet chain between oleic acid, which was physical adsorption, and the amount of oleic acid coated inside were comparable to outside. The diffraction peaks of oleic acid modified Fe3O4and Fe3O4without modified were the same and the grain structure of the modified Fe3O4did not change. What’s more, the diffraction peaks were almost identical with the standard federation (JCPDS) compiled by the standard powder diffraction (PDF) card85-1436. Fe3O4crystal had higher crystallinity. The average size of Fe3O4nanoparticles and modified Fe3O4nanoparticles were11nm and13nm, respectively. The OA-Fe3O4particles modified in appropriate oleic acid dispersed in cyclohexane formed magnetic fluids, and it showed high stability. It was found that self-made magnetic liquid had a high-added value by means of cost budget. |
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